Defense lawyers in the Sept. 11 case said Tuesday that the Pentagon prosecutor is backing away from a national security doctrine that reflexively gags anything the accused 9/11 plotters say to anyone at Guantánamo.

At issue is the controversial theory of “presumptive classification.” Because the accused 9/11 conspirators were held for years in secret custody by the CIA, and are now confined to a secret prison at Guantánamo, anything they say starts off classified as a national security secret.

They are facing a death-penalty trial at the Guantánamo war court, and their defense lawyers have argued that the interpretation has straight-jacketed their trial preparation.

Moreover, the American Civil Liberties Union disputes the concept of “presumptive classification” as being at odds with the public’s right to know what happened to the captives in secret U.S. custody. Agents seized the men in 2002 and 2003, and then turned them over to the military at Guantánamo in 2006.

“Today, the prosecution in the 9/11 military commission filed a document retreating from its argument for ‘presumptive classification’ of all detainee statements, regardless of their topic,” said James Connell, lawyer for Ammar al Baluchi, the nephew of alleged mastermind Khalid Sheik Mohammed. “Defense attorneys have vigorously opposed the practice of presumptive classification.”